There are many examples in the spec that use the XForms XPath functions that are missing the namespace prefix.
The namespace prefix has to be used always in XPath extension functions. (e.g. at="cursor('cartUI') =>
at="xforms:cursor('cartUI')".
Incorrect examples can be found at least in sections:
'7.4.3.1 property()' :
calculate="property('version')"
'7.4.2.5 cursor()' :
at="cursor('cartUI')"
'9.3 repeat : Example: homogeneous coll...'
4 * cursor()
'9.3.2 Nested Repeats' :
cursor()
-mikko